TWI738633B - Manufacturing method of processed objects - Google Patents

Abstract

The present invention relates to an adhesive sheet and a manufacturing method of a processed object. The adhesive sheet provided by the present invention is used to irradiate a plate-shaped component with laser light to form a modified portion, which is used to divide the above-mentioned plate-shaped component into a chip The adhesive sheet has a base material and an adhesive layer provided on one side of the base material. The base material is used for the above-mentioned one side and the opposite sides of the above-mentioned one side in accordance with JIS B0601: 2013 (ISO 4287). : 1997) The prescribed arithmetic average roughness Ra is 0.01 μm or more and 0.2 μm or less, and the thickness of the adhesive layer is 2 μm or more and 12 μm or less. When the adhesive sheet is used in the cutting process using laser light, it is difficult to produce defects and has excellent pick-up properties.

Description

Manufacturing method of processed objects

The present invention relates to an adhesive sheet and a manufacturing method of a processed object; in particular, it relates to an adhesive sheet for irradiating a plate-shaped component with laser light to form a modified part, which is used to separate the plate-shaped component into pieces to obtain a wafer-shaped processed object , And a method for manufacturing wafers and other processed objects using the above-mentioned adhesive sheet.

After forming a loop on the surface of the semiconductor wafer, the back surface of the wafer is polished, the back polishing process is performed to adjust the thickness of the wafer, and the dicing process is performed to slice the wafer into the required wafer size.

Recently, with the shrinking of the size of electronic equipment casings or the increasing demand for semiconductor devices using multi-layered chips, the semiconductor chips constituting the components are continuously being thinned. Therefore, the original thickness of the wafers of about 350μm needs to be thinned. To 50~100μm or below this thickness.

As the fragile component wafers become thinner, the risk of breakage during processing and handling also increases. If such a thin wafer is cut through a high-speed rotating dicing knife, especially on the back of a semiconductor wafer, chip cracks will occur, which will significantly reduce the flexural strength of the wafer.

Therefore, the patent literature discloses the so-called stealth dicing method by irradiating the laser light into the semiconductor wafer, forming a modified part while forming a dicing line at the same time, and cutting the semiconductor wafer based on the modified part (Patent Document 1). According to the invisible dicing method, after irradiating the inside of the semiconductor wafer with laser light to form a modified part, the thin semiconductor wafer is pasted on an adhesive sheet (dicing sheet) composed of a base material and an adhesive layer. After stretching, dividing (cutting) the semiconductor wafer along the cutting line, the semiconductor wafer can be produced at a good yield. In addition, it is also disclosed that after the semiconductor wafer is attached to the dicing sheet, it is irradiated with laser light to form a modified part. By adopting such a process to form the modified part, since there is no need to go through the process of attaching a dicing tape to the fragile wafer, the risk of damage to the fragile wafer can be reduced. In such a case, since a general laser system irradiates the surface of the wafer where the circuit is not formed, it is necessary to irradiate the laser through the dicing sheet.

As in the above-mentioned dicing process, as a processing method, a laser is required in some cases, and in the dicing process, a laser is also used as a tool for accurately aligning plate-shaped components such as semiconductor wafers. In the same cutting process as these cases, when laser light is used, the adhesive sheet used (this adhesive sheet is referred to as "laser cutting sheet" in the patent specification of the present invention) during the use process, the laser In the case that the cutting sheet is transmitted through the laser, it must have excellent penetrability for the laser light.

In order to meet such requirements, for example, Patent Document 2 discloses that as a laser dicing sheet formed of a substrate and an adhesive layer formed on one side, the total light transmittance in the wavelength range of 300 to 400 nm is 60% or more. , Haze is below 20%, the width of the comb is 0.25mm, and the sharpness of penetration is above 30.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2005-229040 Report

[Patent Document 2] Patent No. 5124778

In Patent Document 2, as the above-mentioned laser dicing sheet, the centerline average roughness Ra of one side of the substrate is greater than the centerline average roughness Ra of the other side surface, so that the centerline average roughness Ra is larger. An adhesive layer is formed to form a laser whose centerline average roughness Ra is 0.3~0.7μm as the adhesive layer forming surface, and the centerline average roughness Ra of the opposite side of the substrate is 0.14μm. Cut sheet (Patent Document 2 Example).

This kind of laser dicing sheet has a smooth surface on the side opposite to the surface where the adhesive layer of the substrate is formed on the surface of the laser incident side, which prevents the laser light on the surface of the substrate from being scattered, so as to effectively utilize the laser light.

However, the thickness of semiconductor wafers and other processed objects manufactured on plate-shaped components such as semiconductor wafers using laser dicing sheets tends to become thinner. In addition, recent high-density mounting is continuing, sometimes The substrate is replaced by a polysilicon wafer, and silicon (Si) through electrodes (TSV, Through-Silicon Via) are used to laminate the wafer on top of it. Similarly, when the processed product is thin or the processed product has the structure involved in TSV, the adhesive layer of the laser dicing sheet can be easily peeled off from the processed product attached to the adhesive layer (excellent liftability) ) Is better.

On the other hand, the laser dicing sheet described in Patent Document 2 sometimes has a portion where the adhesive layer cannot be properly formed on the substrate. Such a portion is regarded as a system in the plane view of the laser dicing sheet. Defects, there is a concern that the plate-shaped components of the laser incident for the processing of the plate-shaped components may reach the light unevenness.

The present invention is an adhesive sheet used when laser light is used in the cutting process, and its purpose is to provide an adhesive sheet that is difficult to produce defects and has superior removability, and to provide the use of such an adhesive sheet for plate-shaped components Methods of manufacturing processed objects.

In order to achieve the above object, the inventors of the present invention have intensively studied, by setting the thickness of the adhesive layer to 2 μm or more and 12 μm or less, and the arithmetic average roughness Ra of both sides of the base material to 0.2 μm or less, it is possible to obtain stable The new knowledge of adhesive sheet that reduces the possibility of flaws and has excellent repellency.

The present invention has been completed on the basis of the above-mentioned new knowledge, and its contents are as follows.

(1) An adhesive sheet for forming a modified part by irradiating a laser light on a plate-shaped component, which is used to divide the plate-shaped component into a chip, and is characterized in that it has a substrate and one side of the substrate Adhesive layer provided on the surface, the above-mentioned base material has an arithmetic average roughness Ra specified in JIS B0601:2013 (ISO 4287:1997) of 0.01μm or more for the above-mentioned one side and the opposite sides of the above-mentioned one side. , 0.2μm or less, the thickness of the adhesive layer is 2μm or more and 12μm or less.

(2) The adhesive sheet described in (1) above, which has a haze specified in JIS K7136: 2000 (ISO 14782: 1999), and 0.01% when the substrate side is the incident side Above and below 10%.

(3) The adhesive sheet according to the above item (1) or (2), wherein the adhesive layer contains an acrylic polymer, and the glass transition temperature Tg of the acrylic polymer is above -40°C,- Below 10°C.

(4) The adhesive sheet described in (3) above, wherein the acrylic polymer is polymerized The substance contains a structural unit derived from methyl methacrylate, and the mass ratio of methyl methacrylate to the entire monomer imparted to the acrylic polymer is 5% by mass or more and 20% by mass or less.

(5) The adhesive sheet according to the above (3) or (4), wherein the acrylic polymer has an energy ray polymerizable group.

(6) The adhesive sheet according to any one of the above items (1) to (5), wherein the base material contains a polyolefin-based material.

(7) The adhesive sheet according to any one of the above (1) to (6), wherein the arithmetic average roughness Ra of the substrate is set including the substrate roll pressing.

(8) The adhesive sheet according to the above item (7), wherein the roller used in the roller pressing has a surface composed of a metal material.

(9) A method of manufacturing a processed product, comprising: sticking the adhesive sheet according to any one of the above items (1) to (8) on the surface that is closer to the adhesive layer than the base material One side surface of the adhered body including the plate-shaped component, and the bonding process of obtaining the first laminate having the above-mentioned adhesive sheet and the above-mentioned plate-shaped component; The above-mentioned plate-shaped component on the chip, obtaining a plurality of wafers having the divided body of the above-mentioned plate-shaped component, and arranging the dividing process of the second laminated body formed on the bonding sheet; and dividing the plurality of wafers of the second laminated body An ejecting process in which the parts are separated from the above-mentioned adhesive sheet and the above-mentioned wafer is obtained as a processed product; the feature is that until the start of the above-mentioned dividing process, laser light is irradiated to focus on the focal point set inside the plate-shaped component, A modified part forming process for forming a modified part inside the plate-shaped component.

(10) The method for manufacturing a processed product described in the above item (9), wherein the first laminate provided in the division process has an additional layer between the adhesive layer and the plate-shaped component, and the The dividing process divides the additional layer at the same time. In the ejecting process, the chip separated from the adhesive sheet has the divided body of the plate-shaped component, and the surface of the divided body of the plate-shaped component adjacent to the adhesive sheet is formed Split body of the above additional layer.

(11) The method for manufacturing a processed product described in the above item (10), wherein the additional layer has a protective layer.

(12) The method for manufacturing a processed product described in the above item (11) includes a protective film forming process for forming the protective layer of the first laminate from a protective film forming film until the start of the dividing process.

(13) The method for producing a processed product according to the above item (10), wherein the additional layer has a grain bonding layer.

The present invention provides an adhesive sheet that is hard to produce defects and has superior ejectability. In addition, by using this adhesive sheet, a processed product can be stably manufactured on a plate-shaped component.

Hereinafter, the embodiment of the present invention will be described in detail.

1. Adhesive sheet

The adhesive sheet according to one embodiment of the present invention has a base material and an adhesive layer.

(1) Substrate

The base material of the adhesive sheet according to one embodiment of the present invention has a surface opposite to the adhesive layer (referred to as the "adhesive processed surface" in the patent specification of the present invention) and the opposite surface of the adhesive processed surface (Referred to as the "laser incident surface" in the patent specification of the present invention), the arithmetic average roughness Ra specified in IS B0601:2013 (ISO 4287:1997) (the "arithmetic average roughness" not specified below Ra" all means this) is 0.2μm or less. The arithmetic average roughness Ra through these surfaces is 0.2μm or less, and it is difficult to observe the flaws in the plane view of the adhesive sheet. Therefore, the laser light incident on the substrate side of the adhesive sheet can easily reach the adhesive sheet uniformly. In the case of pasted plate-shaped components, this laser light reaches the plate-shaped components unevenly. For example, a part of the plate-shaped component that is not properly formed with a modified part is generated in the plate-shaped component, which increases the number of plate-shaped components from this part. Possibility of problems such as fragmentation cannot be carried out properly. From the viewpoint of improving the uniformity of the incident laser light, for both the adhesive processing surface and the laser incident surface, the arithmetic average roughness Ra is preferably 0.18 μm or less, preferably 0.16 μm or less, and more Preferably it is 0.14μm or less, and particularly preferably it is 0.12μm or less. From the viewpoint of obtaining an adhesive sheet that is difficult to produce flat-view defects, there is no limit to the lower limit of the arithmetic average roughness Ra for the adhesive processed surface. From the viewpoint of maintaining manufacturing stability, etc., it is preferable that the arithmetic average roughness Ra is 0.01 μm or more for both the adhesive processing surface and the laser incident surface.

The constituent material of the substrate according to one embodiment of the present invention satisfies the relevant conditions for the arithmetic average roughness Ra, and can be used as the substrate of the laser dicing sheet, that is, as long as the laser light of the required wavelength can be used Penetration in a practical range, even in the in-plane direction or with a local thickness In the case of a protruding direction, there is no special restriction on the premise that it can also meet the requirement of being difficult to break. The substrate according to one embodiment of the present invention is usually composed of a film mainly composed of a resin-based material. This film can be a single layer or a laminate.

Specific examples of resin materials included in this film include: random copolymer polypropylene, block copolymer polypropylene and other polypropylene; low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density Polyethylene (HDPE) and other polyethylene; ethylene/vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, ethylene-norbornene copolymer and other ethylene copolymers ; Cyclic olefin polymers such as norbornene resin (COP) polyolefin materials such as polybutene, polybutadiene, and polymethylpentene; polyvinyl chloride materials such as polyvinyl chloride and vinyl chloride copolymers; Polyester materials such as ethylene phthalate and poly(butylene terephthalate); polyurethane materials; polyimide materials; ionic polymer resin materials; homologous alkyl (meth)acrylates Polyacrylic materials such as polymers and alkyl (meth)acrylate copolymers; polystyrene materials; polycarbonate materials; fluororesin materials; and hydrides and denatured products of these resin materials As the main material, resin-based materials, etc. The resin material can also be the bridging material of the above-mentioned materials and the bridging agent. In addition, the "(meth)acrylic acid" in the patent specification of the present invention means both acrylic acid and methacrylic acid, and other similar terms are also the same. The resin-based material provided to the above-mentioned base material may be a single type or a mixture of two types. From the viewpoints of high laser penetration, elongation in the in-plane direction, easiness of local deformation in the thickness direction, and low environmental load, it is preferable that the base material according to one embodiment of the present invention contains a polyolefin-based material Among the polyolefin materials, polypropylene containing random copolymerized polypropylene is preferred.

In the case of a resin-based material-based polyolefin-based material included in the base material, in general, the control of the arithmetic surface roughness Ra on both sides of the base material can be formed by pressing two rolls through a roll in which the base material is embedded. By adjusting the surface materials constituting the rollers and the roughness of the surface, the arithmetic surface roughness Ra of both sides of the substrate is set. Traditionally, the surface of these rollers is generally formed of metal on one side and elastic material like rubber on the other side. Therefore, the arithmetic surface roughness Ra of the surface contacting the base material of the roller formed by the metal surface is acceptable. It is relatively easy to perform with a low value, but it is difficult to perform with a low value for the arithmetic surface roughness Ra of the surface of the substrate contacting the roll formed of an elastic material. Here, like the base material according to one embodiment of the present invention, when it is desired to reduce the double-sided arithmetic surface roughness Ra of the base material, metal is used for both sides of the roll required for roll pressing. The formed surface is better. However, in this case, the relative arrangement of the rolls on both sides and the base material must be more closely controlled than when the surface of one roll is made of an elastic material. The resin material contained in the base material is polyvinyl chloride. In the case of materials, since the substrate can be manufactured by inflation molding, the arithmetic surface roughness Ra of both sides of the substrate can be easily set to a low value. However, because polyvinyl chloride-based materials contain halogen elements, it is better not to use them as a base material in order to reduce the environmental load.

The substrate is a film containing the above-mentioned resin-based material as the main material, and various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers may also be contained in the film. As for the coloring agent, for example, pigments such as titanium dioxide and carbon black, or various dyes. In addition, as for the filler, for example, organic materials such as melamine resin, inorganic materials such as fumed silica, and metallic materials such as nickel steel particles. The content of this additive Although there is no particular limitation, it must be fixed in a range that can perform the required functions of the substrate, especially the function of penetrating laser, without losing the required smoothness and flexibility.

In order to harden the adhesive layer, in the case of using ultraviolet rays as the irradiated energy rays, it is preferable that the base material is transparent to ultraviolet rays. In addition, when an electron beam is used as an energy beam, it is preferable that the base material has electron beam penetration.

In terms of the thickness of the substrate, the adhesive sheet is not particularly limited as long as it can function properly in the various processes described above. It is preferably in the range of 20 to 450 μm, and more preferably in the range of 25 to 200 μm. The range is particularly preferably in the range of 50~150μm.

The Young's modulus of the substrate is preferably 50~500MPa. By keeping the Young's modulus within this range, good ductility can be maintained, while the mechanical strength of the substrate is improved, so that the process properties when forming the adhesive layer are good. For example, when a polyolefin-containing resin film as a substrate is placed in a coating machine, it can prevent the substrate from unexpectedly spreading when tension is applied.

From the viewpoint that it is difficult to block the Young's modulus, and that while improving the mechanical strength, the expandability is relatively good, preferably 60-450 MPa, more preferably 100-420 MPa, and particularly preferably 150-300 MPa.

(2) Adhesive layer

The thickness of the adhesive layer having the adhesive sheet according to one embodiment of the present invention is 2 μm or more and 12 μm or less. When the thickness of the adhesive layer is within the above range and the arithmetic average roughness Ra on both sides of the substrate is within the above-mentioned range, it is possible to obtain a product that is difficult to produce defects from a planar view and has excellent pick-up properties. Bonding piece. From the viewpoint of relatively stably reducing the possibility of occurrence of defects, the thickness of the adhesive layer is preferably 3 μm or more, more preferably 4 μm or more. From the viewpoint of stably realizing an adhesive sheet with superior ejectability, the thickness of the adhesive layer is preferably 10 μm or less, more preferably 8 μm or less, and particularly preferably 6 μm or less.

The adhesive composition used to form the adhesive layer having the adhesive sheet according to one of the embodiments of the present invention is not limited. As the adhesive included in the adhesive composition, for example: Adhesives such as rubber, acrylic, silicone, polyvinyl ether, etc. Hereinafter, a case where the adhesive composition for forming the adhesive layer contains an acrylic adhesive will be described as an example. Due to the excellent transparency of the acrylic adhesive, it is easy to penetrate the laser light.

Acrylic adhesives contain acrylic polymers. The acrylic polymer is a polymer containing a structural unit based on an acrylic compound as a unit constituting the skeleton. The acrylic polymer can be a homopolymer formed by the polymerization of one monomer, or a copolymer formed by the polymerization of multiple monomers. From the viewpoint of easy control of the physical and chemical properties of the polymer, an acrylic polymer-based copolymer is preferred.

The glass transition temperature Tg of the acrylic polymer is preferably -40°C or higher and -10°C or lower. By including acrylic polymer with a glass transition temperature Tg of -40°C or higher in the adhesive composition, it becomes possible to reduce the adhesiveness of the adhesive layer and improve the ejectability. From the viewpoint of more stably obtaining the effect of improving the ejectability, the glass transition temperature Tg of the acrylic polymer is preferably -35°C or higher. After the wafer is divided, the glass transition temperature Tg of the acrylic polymer is preferably -20°C or less from the viewpoint of easy maintenance of the performance of the wafer.

The weight average molecular weight (Mw) of acrylic polymer is not unlimited System, usually 100,000 to 2 million is preferred, and 300,000 to 1.5 million is more preferred. In addition, the molecular weight distribution (Mw/Mn, Mn coefficient average molecular weight) is also not limited, usually 1.0-10, more preferably 1.0-3.0.

The specific types of monomers imparted to the acrylic polymer are not limited, and examples of such monomers include (meth)acrylic acid, (meth)acrylate, acrylonitrile, and the like. As specific examples of (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate, and (meth)acrylate can be given as specific examples. 2-ethylhexyl acrylate, nonyl (meth)acrylate, lauryl (meth)acrylate, pentadecyl (meth)acrylate, octadecyl (meth)acrylate and other alkyl carbon numbers are 1~ Alkyl (meth)acrylate of 18; cycloalkyl (meth)acrylate, benzyl (meth)acrylate, isobornyl acrylate, dicyclopentyl acrylate, dicyclopentenyl acrylate , Dicyclopentenyl hydroxyethyl acrylate, amide acrylate and other (meth)acrylates with a cyclic skeleton; 2-(meth) hydroxyethyl acrylate, 2-(meth) hydroxyethyl acrylate (Meth)acrylates having hydroxyl groups such as propyl ester; (meth)acrylates having epoxy resin groups, such as glycidyl methacrylate and glycidyl acrylate, and the like.

From the viewpoint that the acrylic polymer increases the glass transition temperature Tg, it is preferable to contain methyl methacrylate. Since the acrylic polymer contains methyl methacrylate, from the viewpoint of obtaining a more stable effect, the quality of the methyl methacrylate is better for the entire monomer of the acrylic polymer. 5% by mass or more and 20% by mass or less, more preferably 7% by mass or more and 15% by mass or less.

The acrylic polymer may also be a copolymer containing vinyl acetate, styrene, vinyl acetate, etc. as monomers.

The acrylic polymer may have at least one side of a reactive functional group (hereinafter referred to as "reactive functional group") capable of reacting with the energy ray polymerizable group and the bridging agent.

When the acrylic polymer contains an energy-ray polymerizable group, the adhesive layer is irradiated with energy rays, and it is easier to obtain an adhesive that can lower the adhesiveness to the adherend and has excellent ejectability. piece. As the energy ray polymerizable group, a group having a polymerizable double bond can be exemplified. The preparation method of the acrylic polymer having energy-beam polymerizable group is not limited. As an example of this preparation method, for the acrylic polymer having a functional group containing active hydrogen such as a hydroxyl group, a carboxylic acid group and an amine group , A functional group capable of reacting with the aforementioned functional group such as an isocyanate group, and a substance having an energy ray polymerizable group (specifically, a (meth)acrylic acid ethoxy isocyanate) reactant. In addition, through this adjustment method, the acrylic adhesive contains an energy-ray polymerizable group-containing acrylic polymer. The glass transition temperature Tg of the above-mentioned acrylic polymer refers to a system that can be The functional group to which the functional group is reacted, and the Tg before the reaction of the substance having the energy ray polymerizable group.

When the acrylic polymer has a reactive functional group, the reactive functional group reacts with the bridging agent to adjust the cohesiveness of the adhesive layer and prevent the occurrence of residue in the adherend after the peeling of the adhesive sheet, or make the adhesion The adhesiveness of the agent layer is low, and it is easier to improve the pick-up property and so on. The combination of the reactive functional group and the bridging agent is not limited, and examples of the reactive functional group include groups having active hydrogen such as a hydroxyl group, a carboxylic acid group, and an amino group. As the bridging agent, for example, isocyanate-based bridging agents, epoxy resin-based bridging agents, aziridine-based bridging agents, metal clamp compound-based bridging agents, and the like can be exemplified.

The isocyanate-based bridging agent contains at least a polyisocyanate compound containing a plurality of isocyanate groups. For the polyisocyanate compound, for example, aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, etc.; dicyclohexylmethane-4,4 '-Diisocyanate, bicycloheptane triisocyanate, cyclopentyl diisocyanate, cyclohexyl diisocyanate, methylcyclohexyl diisocyanate, hydrogenated xylene Alicyclic isocyanate compounds such as diisocyanate; acyclic aliphatic isocyanates such as cyclohexane diisocyanate, trimethylcyclohexane diisocyanate, and lysine diisocyanate Acid salt and the biuret body, trimer isocyanate body, compound with isocyanate group, ethylene glycol, trimethylolpropane, sesame oil, etc. and non-aromatic low molecular active hydrogen compound Adducts of the reactants and other denatured bodies.

For epoxy resin bridging agents, for example: 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m -Xylylenediamine, ethylene glycol diglycidyl ether, 1,6-diol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl, glycidylamine, etc.

As far as aziridine-based bridging agents are concerned, for example: diphenylmethane-4,4'-bis(1-aziridine carboxamide), trimethylolpropane tris-β-aziridine propionic acid, tetrakis Methylmethane tris-β-aziridine propionic acid, toluene-2,4-bis(1-aziridine carboxamide), melamine, bisisophthaloyl-1-(2-methyl nitrogen ring) Propane), tri-1-(2-methylaziridine) phosphine, trimethylolpropane tri-β-(2-methyl aziridine) propionate and the like.

Among the metal clamp type bridging agents, the metal atoms include aluminum, zirconium, titanium, zinc, iron, tin and other clamp compounds. Among them, the aluminum clamp compound compounds are more desirable because of their good performance. As the aluminum clamp compound, for example: aluminum diisopropoxide mono-oil acetate, monoisopropoxide aluminum di-oil acetate, monoisopropyl Aluminum Oxide Monooleate Monooleate Acetate Acetate, Diisopropoxy Aluminum Monolauryl Acetate Acetate, Diisopropoxide Aluminum Monostearyl Acetate Acetate, Diiso Propoxy aluminum monoisostearyl acetate and so on.

When the adhesive composition contains an acrylic polymer, the adhesive composition may contain components other than the acrylic polymer. As for this material, an energy-ray polymerizable compound can be cited as an example. Energy-ray polymerizable compounds are compounds that are polymerized by irradiation with energy rays such as ultraviolet rays and electron beams. Examples of the energy-ray polymerizable compounds include low-molecular-weight compounds having energy-ray polymerizable groups (monofunctional, polyfunctional monomers and oligofunctional monomers). Polymer) as an example, specific examples can be: trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, neopentaerythritol triacrylate, pentaerythritol monohydroxypentyl acrylate, pentaerythritol hexyl acrylate, or 1,4-Butene glycol diacrylate, 1,6-hexanediol diacrylate, dicyclopentadiene dimethoxy diacrylate, isobornyl acrylate, etc. containing cycloaliphatic skeleton Acrylate; acrylate compounds such as polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy resin denatured acrylate, and polyether acrylate. This compound has at least one polymerizable double bond in the molecule, and the molecular weight is usually about 100 to 30,000, preferably about 300 to 10,000. The adhesive composition is an acrylic adhesive. When it contains an energy-ray polymerizable group-containing acrylic polymer, even if the adhesive composition does not contain low-molecular-weight compounds with energy-ray polymerizable groups, or only Containing a small amount, by irradiating the adhesive layer with energy rays, the adhesiveness to the adherend can still be reduced. When the content of low molecular weight compounds with energy-beam polymerizable groups in the adhesive composition is large, the receptivity tends to decrease. Therefore, the adhesive composition is an acrylic adhesive. Contains polymerizable groups containing energy rays Acrylic polymers can reduce the amount of low-molecular-weight compounds with energy-ray polymerizable groups, and can further improve the ejectability. When the adhesive composition is an acrylic adhesive, the adhesive composition preferably contains 0 to 30 parts by mass of the energy ray polymerizable compound, and 0 to 15 parts by mass relative to 100 parts by mass of the acrylic polymer. It is better to contain 0-10 parts by mass.

When the adhesive composition contains an energy-ray polymerizable group-containing acrylic polymer, or an energy-ray polymerizable compound, it preferably also contains a photopolymerization initiator. As the photopolymerization initiator, benzoin Compounds, acetophenone compounds, phosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds and other photoinitiators; photosensitizers such as amines and quinones can also be cited as examples. Specifically, Examples can be: 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ester, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile , Dibenzyl, diacetyl, β-chloroanthraquinone, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, etc. By containing a photopolymerization initiator, when ultraviolet rays are used as energy rays, it can be performed with a small amount of irradiation time and irradiation amount.

Examples of the energy ray for reacting the energy ray polymerizable group and the energy ray polymerizable compound include ionizing radiation, that is, X-rays, ultraviolet rays, electron beams, and the like. Among them, it is relatively easy to prepare ultraviolet rays for irradiating equipment.

In the case of using ultraviolet rays as ionizing radiation, in terms of ease of handling, it is sufficient to use near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm. The amount of ultraviolet light can be appropriately selected according to the type of energy ray polymerizable group contained in the adhesive layer, the type of energy ray polymerizable compound, and the thickness of the adhesive layer, usually 50~500mJ/cm ² Around, preferably 100~450mJ/cm ² , more preferably 150~400mJ/cm ² . Further, an ultraviolet line illumination generally 50 ~ 500mW / cm ² or so, preferably based 100 ~ 450mW / cm ^2, more preferably based 150 ~ 400mW / cm ^2. The ultraviolet source is not particularly limited, and for example, a high-pressure mercury lamp, a metal halide lamp, etc. can be used.

In the case of using electron beam as ionizing radiation, the accelerating voltage can be appropriately selected according to the type of energy ray polymerizable group contained in the adhesive layer, the type of energy ray polymerizable compound, and the thickness of the adhesive layer. Generally, acceleration The voltage is around 10~1000kV. In addition, the irradiation dose may be set within a range in which the reaction of the energy-beam polymerizable group and the energy-beam polymerizable compound contained in the adhesive layer can proceed appropriately, and is usually selected in the range of 10 to 1000 krad. The electron beam source is not particularly limited, and examples of Cockcroft-Walton accelerators, Van de Graaff accelerators, resonance transformer accelerators, and insulated core transformer accelerators can be used. , Or various electron beam accelerators such as linear, high-frequency and high-voltage (Dynamitron) accelerators, and high-frequency accelerators.

(3) Optical characteristics

The adhesive sheet according to an embodiment of the present invention has a haze specified in JIS K7136: 2000 (ISO 14782: 1999), when compared with the adhesive layer, when the surface adjacent to the substrate is used as the incident surface, it is 0.01 Above% and below 10% are better. Through the haze of 10% or less, the laser light incident on the adhesive sheet can be effectively utilized. From the viewpoint that the laser light incident on the adhesive sheet can be used more stably and effectively, the above-mentioned haze is preferably 5% or less, more preferably 2.5% or less; from the effective use of the laser light incident on the adhesive sheet From the point of view, the above haze does not set a lower limit; and from From the viewpoint of improving manufacturing stability, the above-mentioned haze is preferably about 0.01% or more.

The adhesive sheet according to one embodiment of the present invention has a total light transmittance specified in JIS K7375:2000. Compared to the adhesive layer, when the surface adjacent to the substrate is used as the incident surface, it is preferably 85% or more . Through the total light transmittance of 85% or more, the laser light incident on the adhesive sheet can be effectively utilized. From the viewpoint of effectively using the laser light incident on the adhesive sheet, the above-mentioned total light transmittance is preferably 90% or more; from the viewpoint of effectively using the laser light incident on the adhesive sheet, the above-mentioned total light transmittance is not The upper limit is set; and from the viewpoint of improving manufacturing stability, etc., the above-mentioned total light transmittance is preferably about 99.99% or less.

(4) Additional layer

In the adhesive sheet according to one embodiment of the present invention, an additional layer is formed on the surface of the adhesive layer side. When the adhesive sheet is used, the plate-shaped component of the adhesive body of the adhesive sheet can also be pasted with the above-mentioned additional layer. The configuration of the additional layer is not limited, and specific examples of the additional layer include a case where the additional layer has a protective film to form a thin film, or a case where the additional layer has a crystal grain bonding layer.

The protective film forming film is cured by external energy such as heat, and is made of a material that can form a protective film. The protective film forms a thin film or a protective film, and the divided body is separated from the adhesive layer in a state where the divided body is attached to a wafer-shaped module formed by dividing the plate-shaped module into pieces. Therefore, when the additional layer-based protective film is formed into a thin film, a processed product formed by laminating a protective film to form a thin film or a divided body of the protective film on one side of the wafer-like component can be obtained.

In the case of an additional layer-based crystal grain bonding layer, the wafer-shaped component formed by slicing the plate-shaped component into pieces is attached to the divided body of the crystal grain bonding layer from The adhesive layer is separated. Therefore, in the case of the additional layer-based crystal grain bonding layer, a processed product formed by laminating a divided body of the crystal grain bonding layer on one side surface of the wafer-like component can be obtained.

(5) Peeling sheet

The adhesive sheet according to one embodiment of the present invention has the purpose of protecting the adhesive layer or additional layer during the period of time until the adhesive layer or additional layer is attached to the plate-shaped component of the adherend. It is also possible to attach the release surface of the release sheet to the surface of the adhesive layer closer to the substrate of the adhesive sheet, specifically, to the surface of the adhesive layer or the surface of the additional layer. The composition of the release sheet is not limited, for example, a release agent can be coated on the plastic film. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, poly(butylene terephthalate), and polyethylene naphthalate, and polyolefin films such as polypropylene or polyethylene. As for the release agent, although polysiloxanes, fluorines, long-chain alkanes, etc. can be exemplified, these are preferably low-priced and stable polysiloxanes. The above-mentioned release sheet can also be used instead of a plastic film, and a paper substrate such as cellophane, coated paper, or forest paper, or a laminated paper in which a thermoplastic resin such as polyethylene is laminated on the paper substrate. Although the thickness of the release sheet is not particularly limited, it is usually about 20 μm or more and 250 μm or less.

2. Manufacturing method of processed objects

By using the adhesive sheet according to one of the embodiments of the present invention described above, a processed product can be manufactured on a plate-shaped component as described below.

(1) Pasting process

First, in the adhesive sheet according to one embodiment of the present invention described above, the surface of the adhesive layer that is closer to the substrate than the substrate, specifically the surface of the adhesive layer or the surface of the additional layer, is attached to the surface containing On one side of the adherent body of the plate-like component, it is obtained with Adhesive sheet and the first laminate of plate-shaped components. There are no restrictions on plate-shaped components, such as semiconductor wafers such as polysilicon wafers, and laminates with structures related to TSVs. The thickness of the plate-shaped component is also unlimited, for example, in the range of tens of μm to hundreds of μm.

The first layered body may have an additional layer, and examples of the additional layer include: a protective film formed on a protective film forming film, a protective film forming film, a crystal grain bonding layer, and the like. The additional layer, as a part of the adhesive sheet, can be pasted on the plate-shaped component, or an additional layer can be laminated on one side of the plate-shaped component in advance. In the latter case, the opposite side of the opposing surface of the plate-shaped component of the additional layer serves as the side surface of the adherend containing the plate-shaped component, and becomes the surface on which the adhesive sheet is adhered.

(2) Segmentation process

By spreading the base material with the first laminate and dividing the plate-shaped components on the adhesive sheet, a second laminate formed by arranging a plurality of wafers of the divided bodies of the plate-shaped components on the adhesive sheet is obtained. When the first laminate has an additional layer, the additional layer is also divided by stretching the base material. After the dividing process is completed, the part of the substrate with a greater degree of extension can be shrunk by heating or other methods, which can also solve the occurrence of excessive relaxation of the adhesive sheet.

(3) Formation process of reforming part

Until the start of the above-mentioned dividing process, the irradiated laser light is focused on the focal point set inside the plate-shaped component, and a modified part is formed in the inside of the plate-shaped component. The wavelength of the laser light and the irradiation method are appropriately set according to the composition and thickness of the plate-shaped component. After the above-mentioned pasting process is completed, in the case of performing the reforming part forming process, the laser light can also be irradiated to the plate-shaped component through the bonding sheet. Even in such a case, the adhesive sheet according to one embodiment of the present invention It is still difficult to produce flaws in a plane view, and the degree of laser light irradiation changes in the flaws and the vicinity, and the problem that the modified part in the plate-shaped component becomes partially inappropriate is also difficult to occur. Similarly, if the modification of the plate-shaped component is partially formed inappropriately, in the above-mentioned dividing process, there is a doubt that the plate-shaped component cannot be properly divided. If the division of the plate-shaped component cannot be performed properly, the possibility of a reduction in the quality of the processed product will increase.

(4) Topping process

By separating the plurality of wafers of the second laminate from the adhesive sheet individually, a wafer as a processed product can be obtained. The separation method is not limited. Usually, the opposite side of the chip of the bonding sheet is topped with a pin, etc., by locally deforming the bonding sheet, the bonding of the bonding agent layer of the chip that is expected to be separated Reduced connectivity. Then, using a vacuum collet (Collet) or the like, the wafer that is expected to be separated is removed from the adhesive sheet to separate the wafer from the adhesive sheet. In this case, when the ejector pin is pulled up or the chip is pulled up from the vacuum collet, the force to remove the adhesive layer will be applied to the chip. This is done when the chip is thin or has the structure involved in TSV. During the removal step, there may be concerns about cracks on the chip. However, since the adhesive sheet according to one embodiment of the present invention has appropriately controlled the thickness of the adhesive layer, when this removal step is performed, the possibility of chip cracking is appropriately reduced, that is, one of the present inventions. The repellency of the adhesive sheet according to the embodiment is very excellent.

In the case where the first laminate has an additional layer, the wafer separated from the adhesive sheet through this pick-up process has a split body of the plate-shaped component and the additional layer formed on the adjacent surface of the adhesive sheet of the split body of the plate-shaped component The division of the layer. That is, during the pick-up process, peeling occurs between the adhesive layer and the split body of the additional layer, and the processed product is separated from the adhesive sheet.

In the case of the additional layer-based protective film of the divided body provided with the additional layer, the time when the protective film is formed on the protective film forming film is not limited. The protective film formation of the additional layer of the first laminate can also be performed until the separation process starts. The additional layer-based protective film forming film of the additional layer imparted to the divided body, and the protective film may be formed on the divided body of the protective film forming film possessed by the processed object.

The above-described embodiments are described to facilitate the understanding of the present invention and should not limit the scope of the present invention. Therefore, they belong to all design changes or equivalents within the technical scope of each element described in the above-mentioned embodiments. All should still fall within the scope of the invention patent.

(Example)

Hereinafter, the present invention will be further specifically described through examples and the like, but the scope of the present invention is not limited by these examples and the like.

[Example 1]

(1) Production of base material

Using a small T-shaped extruder (manufactured by Toyo Seiki Seisaku-sho, Ltd., "Laboplastomill."), a resin composition formed of random copolymer polypropylene resin is used for extrusion molding to produce one side (equivalent to adhesive processing) A thin film with arithmetic surface roughness Ra of 0.03 μm on the surface) and 0.03 μm on the arithmetic surface roughness Ra of the other side (corresponding to the laser incident surface) is used as a substrate. In addition, the surface roughness of the base material was measured with a surface roughness measuring machine (manufactured by Mitutoyo Corporation, "SV-3000").

(2) Preparation of adhesive composition

Combine 62 parts by mass of butyl acrylate and 10 parts by mass of methyl methacrylate Ester, and 28 parts by mass of 2-hydroxyethyl acrylate (HEA) were copolymerized. In the obtained copolymer (glass transition temperature Tg-34°C), methacryloxyethyl isocyanate (MOI) was added to the copolymer 80 mol% of HEA was reacted to obtain an acrylic polymer (weight average molecular weight 500,000) with energy-ray polymerizable groups.

With respect to 100 parts by mass of the acrylic polymer, 3.0 parts by mass of a photopolymerization initiator (manufactured by BASF, "Iragacure 184", concentration: 100%), and an isocyanate compound (manufactured by Toyo Ink Co., Ltd.) , "BHS-8515") 1.0 parts by mass are mixed and then diluted with a solvent to obtain an adhesive composition.

(3) Making of bonding sheet

The above-mentioned adhesive composition was coated on the release surface of the release sheet, and each release sheet was subjected to 1 minute in an environment of 80°C by applying the obtained coating film to obtain a release sheet and an adhesive layer (measured The thickness is 10μm).

Paste the adhesive layer side surface of the laminate on the adhesive processing surface of the aforementioned substrate, and peel off the laminate on the adhesive layer side surface to obtain the substrate and the adhesive layer. Adhesive sheet formed by the agent layer.

[Example 2]

Except that the thickness of the adhesive layer was set to 5 μm, everything else was the same as in Example 1. The adhesive sheet was obtained with the release sheet laminated on the surface on the adhesive layer side.

[Example 3]

Except for the following changes, the rest is the same as in Example 1, and the adhesive sheet is obtained in the state where the release sheet is laminated on the surface of the adhesive layer side.

(Content of change): Change the molding conditions of the substrate, set the arithmetic surface roughness Ra of the adhesive processing surface of the substrate to 0.16μm, and set the arithmetic surface roughness of the laser incident surface The roughness Ra was set to 0.03 μm.

[Comparative Example 1]

Except that the thickness of the adhesive layer was set to 15 μm, everything else was the same as in Example 3. The adhesive sheet was obtained with the release sheet laminated on the adhesive layer.

[Comparative Example 2]

Except for the following changes 1 and 2, the rest is the same as in Example 1, and the adhesive sheet is obtained in the state where the release sheet is laminated on the surface of the adhesive layer side.

(Modification 1): The molding conditions of the substrate were changed, the arithmetic surface roughness Ra of the adhesive processing surface of the substrate was set to 1.3μm, and the arithmetic surface roughness Ra of the laser incident surface was set to 0.04μm.

(Change content 2): The thickness of the adhesive layer is set to 15 μm.

[Comparative Example 3]

Except that the thickness of the adhesive layer was set to 10 μm, everything else was the same as in Comparative Example 2. The adhesive sheet was obtained in a state where the release sheet was laminated on the surface of the adhesive layer side.

[Comparative Example 4]

Except for the following changes, everything else was the same as in Example 1, and the adhesive sheet was obtained in a state where the release sheet was laminated on the surface on the adhesive layer side.

(Content of change): Change the molding conditions of the substrate, the arithmetic surface roughness Ra of the adhesive processing surface of the substrate is set to 0.04μm, and the arithmetic surface roughness Ra of the laser incident surface is set to 1.3μm.

[Test Example 1] <Measurement of Haze>

In the adhesive sheets manufactured in the examples and comparative examples, the release sheet was removed and cut to an appropriate size. The haze of the obtained test sheet was based on JIS K7136: 2000, using HAZE METER (Nippon Denshoku Industries Co. , Ltd., "NDH-5000"). The measurement light was incident on the substrate side surface of the adhesive sheet. The results are shown in Table 1.

[Test Example 2] <Observation of Defects>

In the adhesive sheets manufactured through the examples and comparative examples, after the release sheet was removed, an arbitrary range of 100mm×100mm on the adhesive layer side surface of each adhesive sheet was used as the observation range, and for each of these observation ranges, Observed with an optical microscope, according to the degree of flaws, the following criteria were evaluated. The results are shown in Table 1.

A: No flaws are found in the observation range.

B: Five or less defects are found in the observation range.

C: Six or less defects are found in the observation range.

[Test Example 3] <Rejectability Evaluation>

The adhesive sheets manufactured through the examples and comparative examples were cut into a circular shape in plan view, and after removing the peeling sheet, they were pasted on a polysilicon wafer (thickness: 100μm) and a ring frame (Ring frame). The adhesive layer of the film.

Using a laser irradiation instrument, on the opposite side of the adhesive layer of the polysilicon wafer, scan and irradiate the wafer with a concentrated laser along the predetermined cutting line between the adhesive sheets. An 8mm×8mm wafer is formed inside. After all the cutting lines are irradiated with the laser, use the stretching device to pull the 10mm adhesive sheet at a speed of 10mm/sec. Extend in and out of the main surface.

In this state, irradiate the adhesive sheet with ultraviolet rays under the following conditions.

Illumination: 220mW/cm ²

Light quantity: 190mJ/cm ²

Then made by Aikoh Engineeering Co., Ltd., Push Pull Guage (fixture on top: 1 (Pin)) measures the load during jacking. Measure the load required for topping. According to this measured value, the liftability is evaluated according to the following criteria. The results are shown in Table 1.

A: Below 1.7N

B: larger than 1.7N

It can be seen from Table 1 that the adhesive sheet of the embodiment that satisfies the conditions of the present invention has low haze, is difficult to produce defects, and has excellent pick-up properties, and is an ideal laser dicing sheet.

(Industrial availability)

The adhesive sheet according to the present invention is suitable for use as a laser dicing sheet.

Claims (10)

A method of manufacturing a processed product using an adhesive sheet having a substrate and an adhesive layer provided on one side of the substrate, characterized in that: the substrate is opposite to the one side and the The arithmetic average roughness Ra specified in JIS B0601:2013 (ISO 4287:1997) is 0.01 μm or more and 0.2 μm or less; the above-mentioned base material contains polyolefin-based materials; the above-mentioned base material The arithmetic average roughness Ra is 0.01 μm or more and 0.12 μm or less; the adhesive layer is formed of an adhesive composition containing at least one of an acrylic polymer having an energy ray polymerizable group and an energy ray polymerizable compound; The thickness of the adhesive layer is 2 μm or more and 12 μm or less; the manufacturing method is that the adhesive sheet is adhered to one side of the adhesive body containing the plate-shaped component, which is closer to the surface of the adhesive layer than the substrate Surface, the bonding process of obtaining a first laminate having the adhesive sheet and the plate-shaped component; by extending the base material of the first laminate, dividing the plate-shaped component on the adhesive sheet to obtain the A process for arranging the plurality of wafers of the split body of the plate-shaped component on the second laminate formed on the bonding sheet; and separating the plurality of wafers of the second laminate from the bonding sheet, and using the wafer as The topping process of the processed product; Until the start of the dividing process, the laser light is irradiated to focus on the focal point set inside the plate-shaped component, and the reforming part forming process is formed in the plate-shaped component, and is provided in the dividing process The first laminate has an additional layer between the adhesive layer and the plate-shaped component, and the additional layer is also divided in the dividing process, and in the ejecting process, the wafer separated from the adhesive sheet has the The divided body of the plate-shaped component, and the divided body of the additional layer formed on the surface of the divided body of the plate-shaped component adjacent to the adhesive sheet. According to the manufacturing method of the processed product described in the first item of the patent application, the above-mentioned adhesive sheet has a haze specified in JIS K7136: 2000 (ISO 14782: 1999), when the substrate side is used as the incident side, it is 0.01% Above and below 10%. According to the method of manufacturing a processed product described in the first item of the scope of the patent application, the adhesive layer contains an acrylic polymer, and the glass transition temperature Tg of the acrylic polymer is -40°C or higher and -10°C or lower. According to the manufacturing method of the processed product described in the third item of the scope of the patent application, the acrylic polymer contains a structural unit derived from methyl methacrylate, and the methyl methacrylate which is the entire monomer imparted to the acrylic polymer is The mass ratio is 5% by mass or more and 20% by mass or less. According to the method of manufacturing a processed product described in the third item of the scope of patent application, the acrylic polymer has an energy ray polymerizable group. According to the method of manufacturing a processed product described in the first item of the scope of the patent application, the arithmetic average roughness Ra of the substrate is set including the substrate roll pressing. According to the manufacturing method of processed objects described in item 6 of the scope of patent application, the above The roller used in the roller press has a surface composed of a metal material. According to the manufacturing method of the processed object described in the first item of the scope of patent application, the above-mentioned additional layer has a protective layer. According to the manufacturing method of the processed article described in the scope of the patent application, the protective film forming process of forming the protective layer of the first laminate from a protective film forming thin film until the start of the dividing process is included. According to the method of manufacturing a processed product described in the first item of the scope of patent application, the above-mentioned additional layer has a grain bonding layer.